The present invention relates to improvements in a method and an apparatus for bottling by making use of a counter-pressure gas in a tank, that is a so-called "filler-bowl," for storing the liquid to be bottled.
Counter-pressure type bottling valve assemblies and methods for operating the same have been heretofore known and widely used in practice. Now in order to highlight the disadvantages of such prior art apparatuses and methods, by way of example, a specific structure of the bottling valve assembly and a method for operating the same in accordance with the prior art will be described in detail with reference to FIGS. 1 through 6 of the accompanying drawings.
In FIGS. 1 and 2, an outer valve actuating lever 1 and an inner valve actuating lever 3 integrally connected to the former via a shaft 2 are rotatably mounted on a side wall of a filler-bowl 4 (not shown except for a cross-section of its bottom wall, but to be described in detail later in connection with FIGS. 7 to 9). It is to be noted that in FIG. 1 the outer valve actuating lever 1 is shown by a solid line in the closed position thereof designated by a, and also shown partly by a dot-dash line in the opened position designated by b. Reference numeral 5 generally designates a charging valve member consisting of an upper valve body 5a, a lower valve body 5b and a packing 6 sandwiched therebetween, the lower valve body 5b is in a freely slidable relation with respect to a stem 7, and a spring 8 is compressed between the stem 7 and the lower valve body 5b, whereby the charging valve member 5 is supported through the spring 8 as floating above the stem 7. Reference numeral 5 c designates a vent hole, and a pneumatic valve is formed by charging valve member 5, packing 6 and stem 7. On the stem 7 is fixedly secured a collar 9, which is upwardly biased by a spring 10 in a spring case 11. At the bottom of the stem 7, an annular packing 12 is fixedly contained in an annular groove, and a subject liquid valve is formed by the packing 12 and a snift block 13. The snift block 13 includes a snift valve consisting of a cap nut 14, a snift stem 15, a packing 16 and a spring 17, as well as a snift orifice 18. Under the snift block 13 are provided an outer centering cup 19 and an inner centering cup 20, and these members are mounted to the filler-bowl 4 via a packing 22 by means of a metal mounting piece 21. In addition, to the bottom of the stem 7 is screwed a vent tube 23, a spreader 24 is mounted on the vent tube 23, and a vent hole 25 is drilled in a side wall of the vent tube 23 beneath the spreader 24. Reference numeral 26 designates an empty bottle to be filled with the subject liquid. The bottle neck is pressed against the inner centering cup 20 so as to eliminate any leakage between the neck of the bottle and the inner centering cup 20 by pushing up the empty bottle 26 from its bottom side by means of a pneumatic cylinder 27. Reference numeral 11a designates liquid passageways formed in spring case 11. FIG. 2 shows the same bottling valve assembly in a different state where the outer valve actuating lever 1 and the inner valve actuating lever 3 are shown as displaced to the position b, that is, in a bottling state where the subject liquid valve and the pneumatic valve are both opened, with the vent tube 23 and the stem 7 raised by a dimension equal to c while the charging valve 5 is raised by a dimension equal to d with respect to the state shown in FIG. 1. Dimensions c and d are established such that c&lt;d. It is to be noted that the above-referred stroke c of the valve stem 7 is defined by the limiting effect that an upper edge of a radial stopper fin 7b fixedly secured to a radially expanded bottom portion 7a of the valve stem 7 strikes against a downward inner shoulder portion of the spring case 11, while the above-referred stroke d of the charging valve 5 is defined by the linear stroke of the inner valve actuating lever 3.
Now the bottling process in the prior art will be described with reference to FIGS. 1 through 6. At first, when the bottle 26 has been raised by means of the pneumatic cylinder 27, the state shown in FIG. 1 is established, but in this state the subject liquid has not been filled into the bottle. In the state shown in FIG. 1, if the outer valve actuating lever 1 and the inner valve actuating lever 3 are displaced from the position a to the position b, then the charging valve 5 is raised, and only the valve 5 takes the position shown in FIG. 2. Subsequently, the pressurized gas at a predetermined counter pressure (normally at 2-4 kg/cm.sup.2 .multidot.G) within the filler-bowl 4 flows in directions opposite to the arrows 28, 29 and 30, so that the inner pressure of the bottle 26 is also raised to the same pressure as that maintained within the filler-bowl 4. Consequently, the spring 10 compressed between the collar 9 and an upward inner shoulder portion of the spring case 11 pushes up the valve stem 7 and the vent tube 23 via the collar 9 until the upper edge of the radial stopper fin 7b strikes against the downward inner shoulder portion of the spring case 11, and thereby the state shown in FIG. 2 is established. Then the subject liquid flows into the bottle 26 along the path represented by arrows 31, 32, 33, 34, 35 and 36, while the gas in the bottle 26 is returned to the filler-bowl 4 through the path represented by arrows 30, 29 and 28, and in this way the bottling operation proceeds. Subsequently when the liquid surface 37 in the bottle 26 has risen up to the level where the vent hole 25 is blocked, the gas flow represented by the arrow 30 is interrupted. At this moment, the flow of the subject liquid represented by arrow 33 is also interrupted at the top end portion of the snift block 13 but the subject liquid then flowing through the portions represented by the arrows 34 and 35 will fall into the bottle 26, and the liquid surface within the bottle 26 eventually takes the level shown at 38 in FIG. 1. At the same time, the subject liquid also enters the inner hollow space of the valve stem 7 and the space is filled with the subject liquid up to the level shown at 39. Here, if the outer valve actuating lever 1 and the inner valve actuating lever 3 in FIG. 1 are returned to the position a, then the state shown in FIG. 1, that is, the state where the subject liquid valve and the pneumatic valve have been both closed after bottling, can be established. At this time, in the upper hollow section 40 of the valve stem 7 and in the upper empty section 41 of the bottle 26 there is maintained the counter-pressure. Then, if the snift stem 15 is pushed in the direction of arrow 42, the snift valve is opened, so that the counter-pressure in the sections 40 and 41 is released to the atmosphere as choked by the snift orifice 18. In other words, owing to the snifting operation, the pressure in the sections 40 and 41 gradually returns to the atmospheric pressure. Nextly, the bottle 26 is removed from the bottling valve assembly by lowering the pneumatic cylinder 27.
In the heretofore known bottling valve assembly, the above-described bottling process is repeated, and in such case the following disadvantages occur. That is, in the above-described process, when the gas confined in the section 40 is released through the vent hole 25, since the gas passes through the liquid within the bottle 26 in the form of bubbles as shown in FIG. 3, separation of carbonic acid gas dissolved in the subject liquid from the subject liquid is promoted by the snift shock, so that there occurs the disadvantage that the bubbles of the separated carbonic acid gas overflow during the step of removing the bottle 26 from the bottling valve assembly as shown in FIG. 4.
In addition, upon bottling fruit juice or the like (normally bottled as heated at about 90.degree. C. and carbonic acid gas not being contained in the subject liquid) it is necessary to set the surface of the liquid contents just after bottling at such level that the dimension h in FIG. 6 is kept at about 5 mm, but this is impossible because of the snifting operation for the counter-pressure gas in the section 40. More particularly, if the surface of the liquid contents is set so that the dimension h is about 5 mm, then due to the falling of the liquid along the inner surface of the bottle and falling of the liquid in the section of the valve stem 7 up to the level 39 upon snifting, the liquid surface level would be raised above the top surface of the neck of the bottle, so that at the moment when the inner centering cup 20 and the neck of the bottle have been separated from each other, the liquid would overflow out of the bottle. This makes normal bottling impossible, and therefore, the above-describe prior art bottling valve assembly cannot be used for fruit juice. It has commonly been impossible to use the same bottling valve assembly both for soft drinks containing carbonic acid gas and fruit juice drinks without carbonic acid gas.
Furthermore, in the heretofore known bottling valve assembly shown in FIG. 1, the minimum value for the dimension h representing the level of the surface of the contents in FIG. 6 was 15-20 mm. The reasons are as follows. That is, because of the falling of the liquid flowing through the sections represented by the arrows 34 and 35 in FIG. 2 into the bottle during the step where the liquid level 37 within the bottle rises and eventually blocks the vent hole 25, as well as the falling of the subject liquid within the valve stem 7 from the level 39 in FIG. 1 into the bottle 26 during the step of opening the snift valve by pushing the snift stem 15, the highest possible level of the liquid surface within the bottle after completion of the above-mentioned steps could be nearly at the liquid level 43 shown in FIG. 5. (If the liquid level 43 is raised higher than the spreader 24, then when the bottle 26 is lowered in the next step, then some of the subject liquid would be pulled or scraped up by the spreader 24, so that overflow of the liquid would occur. In other words, the state where in-flow of the liquid from the bottling valve assembly into the bottle has been interrupted, is considered to be the state where the pressure in the head space within the bottle is balanced with the head pressure of the falling liquid. Accordingly, when the liquid level in the bottle rises up to the vent hole 25, and thereby the release path for the gas within the bottle has been blocked, the pressure within the bottle rises and pushes the liquid nearly up to the level 39 where the gas pressure within the bottle is balanced with the liquid head pressure of the liquid column under the level 39. It is to be noted that when this state is established the liquid having been flowing along the inner bottle wall has already fallen into the bottle. Thereafter, when the head space of the bottle neck is snifted by closing both the pneumatic valve and the liquid valve, the head space of the bottle neck is released to the atmospheric pressure, naturally the compressed gas confined between the liquid level 39 and the upper valve body 5a is also released to the atmospheric pressure, so that the liquid within the stem 7 under the level 39 falls into the bottle, and thus forms the highest liquid level 43 in FIG. 5. Subsequently, when the bottle has been lowered relative to the bottling valve assembly, the liquid level 38 is lowered by the depth corresponding to the volume of the vent tube 23, and after all, the dimension h for the highest liquid level as defined in FIG. 6 falls to within the range of h = 15-20 mm.